Velvet Worm

Velvet worms are amazing little creatures that share some of the features of both arthropods and annelids. While arthropods are invertebrates with exoskeletons, segmented bodies and jointed appendages, annelids are segmented worms. Velvet worms look like worms, but are not true worms and do not belong to the phylum of segmented worms called Annelida. Though, velvet worms are segmented (outwardly inconspicuous) and worm-like, they are closely related to the phylum Arthropada. These creatures belong to the phylum Onychophora, which has two surviving families called Peripatidae and Peripatopsidae with around 230 species. These little creatures are renowned for their unique preying and eating habits. Velvet worms are also unique in their appearance, mating and reproduction.

Velvet Worm - Physical Features

Now, you know that velvet worms are worm-like invertebrates and are not true worms. They are small in size and grow up to a length of around two to twenty centimeters. They are terrestrial and nocturnal and have around 13 to 43 pairs of clawed legs. The body color of velvet worms ranges between blue-gray, orange, red or brown, but, sometimes, you may also find these creatures with a skin color of bright green, blue, gold, white, etc. Most of them have intricate patterns on their bodies. They have segmented bodies, but, the segments are largely inconspicuous and are not easily identifiable from outside. The body is covered with a cuticle that has numerous papillae with fine sensitive hair, that give the velvety sheen. Locomotion is facilitated through changes in the hydrostatic pressure inside the fluid filled body of velvet worm.

The head of a velvet worm has ringed antennae, that are located on the top and on the base of the antennae, eyes can be found. The mouth of this invertebrate is located on the underside of the head and has one oral papillae on either side. These tube-like projections are used to spray slime on prey, which gets trapped in that quick-hardening adhesive. They have two mandibles with fine teeth, that help the creature to feed on the trapped prey. This creature has a tube-shaped heart and an open circulatory system. However, the blood of this animal does not carry oxygen. Oxygen is absorbed through the numerous minute openings on the skin, called trachea. Unlike, insects, velvet worms are not capable of controlling these openings, which remain open and causes water loss.

Feeding and Reproduction

Velvet worms are carnivorous and feed on isopods (like, wood lice), termites, slugs, cockroaches, bark lice, millipedes, centipedes, spiders, worms, snails, etc. They spray slime over the prey at a very high speed. It is said that they can spray slime up to a distance of about 50 centimeters. This quick-release slime gets hardened quickly, thereby inhibiting the movements of the prey. The larger the prey, they need large amounts of slime. Once the prey gets debilitated with the slime, the velvet worm injects digestive enzymes to the body of the prey. After that, the partially digested tissues of the prey are sucked by it. The slime produced by these worms are also used as a defense, as velvet worms spray this slime on the face and eyes of the predator, causing temporary blindness.

Another unique feature of velvet worms is that some species give birth to live young ones. There are some egg-laying species too. The males are often found to be smaller than females. The sperms are deposited either or the genital opening of the female or on the back or sides of the female's body. In the latter case, the sperms are absorbed to the body, through the skin and thereby fertilizing the eggs. Velvet worm habitat includes moist and humid areas, like, leaf litter, rotting tree barks, etc. They are sensitive to light and are mostly nocturnal. They are mainly seen in tropical regions, like, Central and South America, West and South Africa; northeastern India, Indonesia, Malaysia, New Guinea, Australia and New Zealand.

Now, you know more about what are velvet worms and have a basic idea about some interesting velvet worm facts. Due to the unique features and intriguing appearance, these creatures are getting very popular as pets too.